(As every test match is loss making affair unless one of BIG-3 team is playing) but the relegation system came up in existence because of a lopsided fixture in the form of bilateral. Call it the chicken-egg problem.
By the way, how the matches between BIG 3 and other team is a money making affair ? I think it is only the matches between BIG 3 that may only generate expected revenue.
ICC needs to realize that advertisers will be more interested in matches that are more widely viewed by the public and public would like to see the close matches no matter who is playing. For Example, I would be more interested to see a test match between West Indies and Sri Lanka as compared to a match between India and Zimbabwe. Similarly, a one sided match between Australia and Sri Lanka may not be watched but viewers would be more willing to see a test match between Afghanistan and South Africa.